An integral pressure relief assembly is comprised within a roller assembly of a roller reamer. The integral pressure relief assembly extends through a pair of pillow blocks and a bearing shaft of a retention assembly of the roller assembly. A volume of lubricant is inserted under pressure through a relief valve into an interior channel of the bearing shaft. A spring element in combination with an elastomeric piston provides additional pressure to the pressurized volume of lubricant contained within the integral pressure relief assembly. The lubricant absorbs heat from motion of the bearing shaft and a cutter assembly. As the lubricant increases in pressure, the relief valve releases lubricant from the bearing shaft when a sufficient differential pressure between the contained lubricant and the outside environment is achieved.

An integral pressure relief assembly is comprised within a roller assembly of a roller reamer. The integral pressure relief assembly extends through a pair of pillow blocks and a bearing shaft of a retention assembly of the roller assembly. A volume of lubricant is inserted under pressure through a relief valve into an interior channel of the bearing shaft. A spring element in combination with an elastomeric piston provides additional pressure to the pressurized volume of lubricant contained within the integral pressure relief assembly. The lubricant absorbs heat from motion of the bearing shaft and a cutter assembly. As the lubricant increases in pressure, the relief valve releases lubricant from the bearing shaft when a sufficient differential pressure between the contained lubricant and the outside environment is achieved.

At least one mechanical face seal is disposed within a cutter cartridge of a roller reamer. The cutter cartridge includes a roller cutter and a retention assembly. A bearing shaft of the retention assembly extends through an inner channel of the roller cutter. A first mechanical face seal is disposed or shared between the roller cutter and a first pillow block of the retention assembly. An optional second mechanical face seal is disposed or shared between the roller cutter and a second pillow block of the retention assembly. Each pillow block is rotatably coupled at an opposing end of the bearing shaft. The retention assembly includes two separately matched sets of one pillow block and a wedge. The wedges in combination detachably secure the pillow blocks to a tool body of the roller reamer.

At least one mechanical face seal is disposed within a cutter cartridge of a roller reamer. The cutter cartridge includes a roller cutter and a retention assembly. A bearing shaft of the retention assembly extends through an inner channel of the roller cutter. A first mechanical face seal is disposed or shared between the roller cutter and a first pillow block of the retention assembly. An optional second mechanical face seal is disposed or shared between the roller cutter and a second pillow block of the retention assembly. Each pillow block is rotatably coupled at an opposing end of the bearing shaft. The retention assembly includes two separately matched sets of one pillow block and a wedge. The wedges in combination detachably secure the pillow blocks to a tool body of the roller reamer.

At least one labyrinth seal assembly is disposed within a roller cutter of a roller reamer. A first labyrinth seal assembly of a roller cutter is positioned toward a first pillow block of a cutter cartridge that includes the roller cutter. An optional second labyrinth seal assembly is disposed within the roller cutter and toward second pillow block of the cutter cartridge A bearing shaft of the cutter cartridge extends through an inner channel of the roller cutter. The cutter cartridge is retained in an axial recess of a tool body of the roller reamer via a compound and separate wedging of each of the two pillow blocks into a same axial recess. Each pillow block is rotatably coupled to the bearing shaft at an opposing end of the roller cutter.

At least one labyrinth seal assembly is disposed within a roller cutter of a roller reamer. A first labyrinth seal assembly of a roller cutter is positioned toward a first pillow block of a cutter cartridge that includes the roller cutter. An optional second labyrinth seal assembly is disposed within the roller cutter and toward second pillow block of the cutter cartridge A bearing shaft of the cutter cartridge extends through an inner channel of the roller cutter. The cutter cartridge is retained in an axial recess of a tool body of the roller reamer via a compound and separate wedging of each of the two pillow blocks into a same axial recess. Each pillow block is rotatably coupled to the bearing shaft at an opposing end of the roller cutter.

In some aspects, the present disclosure includes systems and methods for rotatably coupling a bottom-hole assembly to a drilling shaft for use in subterranean drilling operations. In one embodiment, the methods of the present disclosure are suitable for underreaming a portion of a wellbore. The methods may comprise rotating a drilling shaft coupled to a drill bit about its axis to form a wellbore; engaging a first locking mechanism rotatably coupled to the drilling shaft with a second locking mechanism coupled to a housing to rotatably couple the drilling shaft and the housing; expanding an expandable reamer attached to the housing; and rotating the housing to widen at least a portion of the wellbore uphole from the drill bit. The bottom-hole may comprise one or more actuators that are selectively operable to engage the first and second locking mechanisms and expand the expandable reamer.

There is a cutter assembly for a roller reamer for downhole drilling. The cutter assembly has a first end block and a cutting element having a plurality of cutting projections. The cutting element is rotatably mounted to the first end block. The cutter assembly further has (a) a primary locking assembly having a primary bore in the first end block for screwing in a primary screw to attach the cutter assembly to a reamer body and (b) a secondary locking assembly. The secondary locking assembly has a secondary bore in the first end block having a threaded section and a secondary bolt screwed into the threaded section. The secondary bolt has a head and a threaded portion. The secondary bolt is for unscrewing out such that the head is received in a locking bore of the reamer body to attach the cutter assembly to the reamer body.

There is a cutter assembly for a roller reamer for downhole drilling. The cutter assembly has a first end block and a cutting element having a plurality of cutting projections. The cutting element is rotatably mounted to the first end block. The cutter assembly further has (a) a primary locking assembly having a primary bore in the first end block for screwing in a primary screw to attach the cutter assembly to a reamer body and (b) a secondary locking assembly. The secondary locking assembly has a secondary bore in the first end block having a threaded section and a secondary bolt screwed into the threaded section. The secondary bolt has a head and a threaded portion. The secondary bolt is for unscrewing out such that the head is received in a locking bore of the reamer body to attach the cutter assembly to the reamer body.

A downhole tool, comprising: a mandrel having first and second opposing ends and an outer mounting surface, the first end comprising a male threaded portion; a tool component mountable on the mounting surface by sliding said tool component onto the mounting surface from the first end of the mandrel; and a load sleeve defining a torque shoulder, wherein the load sleeve is mountable on the mandrel and securable adjacent the male threaded portion of the first end of the mandrel such that the torque shoulder and the male threaded portion define a pin connector to facilitate connection with a box connector of a separate component.